1. Field of the Invention
The present invention relates to an operation knob operated when air direction is adjusted in a register utilized for air-conditioning of a vehicle.
2. Description of Related Art
Conventionally, in a register utilized for air-conditioning of a vehicle, a plurality of vertical fins are rotatably supported in a retainer so as to be able to rotate in a right and left direction, and one or a plurality of lateral fins are slidably supported near an air outlet of the retainer so as to be able to rotate in an up and down direction. Further, the register is constructed so that an operation knob slidably disposed in one lateral fin and the vertical fins are mutually connected through one of various connection mechanisms
In such register, each of the vertical fins is simultaneously rotated together in the right and left direction through the connection mechanism based on that the operation knob is slid in the right and left direction, and each of the lateral fins is simultaneously rotated together in the up and down direction based on that the operation knob is moved in the up and down direction.
As for the operation knob used in the above conventional register, the operation knob is generally constructed from two knob members of an upper knob member and a lower knob member, and both knob members are resiliently engaged with each other while sandwiching both sides of the lateral fine between the upper knob member and the lower knob member.
Since such kind of the operation knob is constructed from two knob members, cost of the operation knob rises and the process to assemble two knob members on both sides of the lateral fin is necessitated, thus such assembling process becomes the cause for cost rising of the operation knob.
Therefore, in order to reduce cost of the operation knob and simplify assemble process of the operation knob to the lateral fin, it is proposed in Japanese Publication laid open No. 2014-148190 an operation knob which is formed into one body as one member and assembled to the lateral fin.
Concretely, in the above Japanese Publication laid open No. 2014-148190, in order to form the operation knob into one body, it is disclosed an operation knob in which an opening is formed at a side opposite to a vertical fin and two gear parts is divisionally formed at both upper and lower sides of the opening, two gear parts being meshed with a gear formed on the vertical fin. By adopting this construction of the operation knob, the operation knob can be formed into one body from resin while using two upper and lower dies and a plurality of movable dies.
When the operation knob disclosed in the above Japanese Publication No. 2014-148190 is attached to the lateral fin, the lateral fin is inserted in one of side openings formed at both side of the operation knob. At that time, the operation knob is attached to the lateral fin by resiliently deforming the side opening. However, there may be a case that this attaching method becomes rather difficult. Therefore, the operation knob is formed into one body as shown in FIGS. 12 and 13, thereby attaching of the operation knob to the lateral fin may become easier.
Concretely, as shown in FIG. 12, an opening 102 is formed at a rear end 101 (left side end portion in FIG. 12) of an operation knob 100 formed into one body. At an upper side and a lower side of the opening 102, an upper gear part 103 and a lower gear part 104 are divisionally formed, both gear parts 103 and 104 being meshed with a gear part (not shown) formed on a vertical fin (not shown).
At the rear end 101 of the operation knob 100, an enclosing wall 105 forming enclosure of the opening 102 is cut and separated at a right lower end portion. Concretely, a clearance 110 is formed between a lower end surface 107 of a lower extended portion 106 forming a right side portion of the opening 102 and an upper surface 109 of a lateral extended portion 108 to the right direction from the lower gear portion 104, the upper surface 109 facing to the lower end surface 107. Based on existence of this clearance 110, the upper part and the lower part of the operation knob 100 may become movable within a range of the clearance 110.
Accordingly, as shown in FIG. 13, when the lateral fin 112 is inserted in one (fin insertion opening at the right side in FIGS. 12 and 13) of fin insertion openings 111 formed at both sides of the operation knob 100, both of the upper part and the lower part of the operation knob 100 are resiliently deformed in a direction to enlarge the clearance 110 according to insertion of the lateral fin 112. Thereby, the lateral fin 112 can be attached to the operation knob 100.
However, since the operation knob 100 is formed from resin material, the upper part and lower part of the operation knob 100 may be easily deformed in a direction that the lower end surface 107 of the lower extended portion 106 and the upper surface 109 of the lateral extended portion 108 mutually approach, that is, in a direction that the clearance 110 becomes narrow.
As mentioned, when the lower extended portion 106 and the lateral extended portion 108 deforms in the direction that the clearance 110 becomes narrow, a sliding portion 113 contacting to and sliding on the lower surface of the lateral fin 112 unnecessarily and strongly interferes with the lateral fin 112. As a result, there is a problem that operation load of the operation knob 100 against the lateral fin 112 increases, thus sliding operability of the operation knob 100 is spoiled.